Hate and evolutionary psychology

Rwandan Hutus controlled the army and the government while Tutsis were kept out. In 1994 the president of Rwanda was assassinated. Immediately the Hutu army began to carry out a systematic campaign of genocide against Tutsis and moderate Hutus. UN guards protecting transitional Prime Minister were tortured, mutilated and killed. The minister of labor was cut into three pieces and used as a roadblock. Men, women and children were massacred in the Red Cross refugee camps where they sought protection. Patients were hacked to death in a hospital. Families inside a mission were blown up with grenades, then doused with gasoline and set on fire. The survivors who tried to run away were cut down with machetes. A woman with no wounds was hauled out of the lake Victoria. She had five children tied to her. One on each arm. One on each leg. One on her back. The number dead was as high as half a million, whose blood flowed out of the country. (6)

The above facts constitute an instance of cruelviolence promoted by homospecieshate.
Is this kind of extreme violence uniquely a human attribute as a result of having broken the rules of nature? Or is it rooted in prehuman history?
It has been thought that only humans deliberately kill members of their own species, whereas animals -often males in sexual competition- fight with others of their own species, but the contest typically ends when one competitor gives up. Also, defense of territory is widespread among many species. (4)

Jane Goodall established her camp in a Tanzania park known as Kasekela, and began giving bananas to the chimpanzees in order to keep them near the camp. By 1966 all of Kasekela chimpanzees interacted peaceably but two communities were identified: the original one, and the southern breakoff (Kahama). By 1971 the adult males in the northern subgroup and those from the south met less and less due to rivalry of two top dominant males, while females kept mating with males of no matter which group. Also there was some local violence, mainly against females. For example, an alpha male attacked a young mother and, grabbing at her baby, hit her with him.

What follows is the first instance -recorded in 1974- of systematic murderous violence among nonhumans.

A group of males and one female-chimpanzees traveled southward and soon they were in the neighbors' territory. A young male and one female of the Kahama group ate peacefully. The alpha male intruder jumped on and kept him immobilized, his face crushed into the dirt. The other males pummeled his back, and bit their victim viciously -wounding him in the mouth, forehead and nose, and broke one leg. The alpha male grabbed him by the neck, drank the blood streaming down his face, and ripped and emptied his scrotum. Then pulled the young down a hill, and the Kahama female was forced to join their party. The aggressors hurried deeper into the Kahama territory, hooting and charging. Eventually they returned to their range.
This first attack was ensued by several ones, and feeding was never its reason. Sometimes intruders made a mistake -charging toward a party- that, despite seeming small at first proved large, led to a confused retreat by the invaders. Remorselessly, however, one by one all adult males and some females of the Kahama community disappeared, the remainder females being transferred to Kasekale group. By the end of 1977 they had expanded their territory into the Kahama core. (1,6)

Similar actions also occur elsewhere in Africa lands, where no artificial provisioning has taken place. And these expeditions are not just defense but purposeful raids fraught with -seemingly- needless cruelty.

Sharing with chimpanzees the propensity to raiding make humans a little less special. However no species is more closely related to humans than chimpanzees are (DNAdivergence between both is 5%.) These species separated 5 million years ago, and because of chimps remained in the not much changed rain-forest environment since then, they are proper models of our common ancestors.

It is possible that the ultimate explanation of any individual's behavior consists of maximizing genetic success by passing individual's genes into subsequent generations. A general principle by which behavior evolves to serve selfish ends make reasonable the idea that both humans and chimps might have been favoured by natural selection to beat their competitors to pulp. (5)

Nevertheless, why did not such intensely violent behavior evolve in other animals?
Very few animals live in patrilineal communities wherein females reduce the risks of inbreeding by moving to neighboring groups to mate. After a fight, the winner's testosterone level rises, but the loser's falls, and the winner feels good, but the loser feels bad. It is reasonable to imagine that this winner-effect results in more success for the winner to mate: many women find attractive behaviours such as successful aggression and display of dominance often associated with male personality. (4)
Thus, both men and women are active participants in the system that nurtures the continued success of perverse males.

On the other hand, if men and chimps are so violent why do they seek out to hurt only people such as females, minorities and unarmed groups? Lions, for instance, infrequently are involved in a lethal fight despite their tremendous ferocity and strength. The answer to this paradox is likely that they have got a harem of devote females, and all they need is to consolidate their position. Lion, chimp and man act as if they are driven to reach the top of the community heap. But once the authority is no longer challenged, the tendency for intragroup violence falls significantly. Here the lion stops, but men and chimpanzees have been favoured by natural selection to attack victims weaker than themselves. And one more stable evolutive strategy consists of alpha males forming coalitions with their followers in mutual support against others in order to improve the genetic pool by exterminating the lamer opponents. (4)

Furthermore, the ultimate result of such kind of behaviour is an emotional reward which is not merely an increased likelihood of mating but just the pleasing feel that both the power itself and pride bestow.

And what about cruelty? Fierceness goal is dissuading, intimidating the opposition, and to erode its ability to challenge. This strategy eases the aggressors winning without themselves being harmed.

Should we assume that this violence pattern is the main support for men to drive their evolution? Probably so is it: the system of communities that consider best defense is attack has been established as a human universal that crosses space and time.

A gloomy future seems waiting for us because of the increasing strenght and power of the survivors among the opponent groups. However moral sense -the part of human nature that passes judgment on actions- probably might be the most efficient mechanism capable of restraining the human violent behaviour. Time will tell.(2,3,7)